Hybrid Beamforming Transmission Method and Network Device

1. A hybrid beamforming transmission method, comprising steps of: determining, by a network device, a digital-domain beamforming weight matrix for a first User Equipment (UE) in accordance with a channel measurement result; determining, by the network device, a set of beamforming weight matrices in accordance with the digital-domain beamforming weight matrix, and transmitting a signal to the first UE in an analog beamforming manner; selecting, by the network device, a beamforming weight matrix from the set of beamforming weight matrices in accordance with a measurement result from the first UE, as an analog-domain beamforming weight matrix for the first UE; and performing, by the network device, hybrid beamforming transmission in accordance with the determined digital-domain beamforming weight matrix and the selected analog-domain beamforming weight matrix.

2. The hybrid beamforming transmission method according to claim 1 , wherein the step of determining, by the network device, the digital-domain beamforming weight matrix for the first UE in accordance with the channel measurement result comprises transmitting, by the network device, a downlink reference signal, receiving from the first UE a Precoding Matrix Indicator (PMI) acquired by performing downlink channel measurement in accordance with the downlink reference signal, and determining the corresponding digital-domain beamforming weight matrix in accordance with the PMI.

3. The hybrid beamforming transmission method according to claim 1 , wherein the step of determining, by the network device, the digital-domain beamforming weight matrix in accordance with the channel measurement result comprises: measuring, by the network device, an uplink signal from the first UE to acquire digital-domain Channel State Information (CSI); and determining, by the network device, the digital-domain beamforming weight matrix for the first UE in accordance with the digital-domain CSI and a digital-domain beamforming method adopted thereby.

4. The hybrid beamforming transmission method according to claim 1 , wherein the set of beamforming weight matrices correspond to a spatial range, and a beam corresponding to each beamforming weight matrix in the set of beamforming weight matrices is located within the spatial range.

5. The hybrid beamforming transmission method according to claim 4 , wherein the step of selecting, by the network device, the beamforming weight matrix from the set of beamforming weight matrices in accordance with the measurement result from the first UE as the analog-domain beamforming weight matrix for the first UE comprises: receiving, by the network device, information about an index of the beamforming weight matrix fed back by the first UE with respect to the signal; and determining, by the network device, the corresponding analog-domain beamforming weight matrix in accordance with the information about the index of the beamforming weight matrix fed back by the first UE, wherein the first UE is configured to measure the signal, select the corresponding beamforming weight matrix from the set of beamforming weight matrices in accordance with a measurement result, and feed back the information about the index of the selected beamforming weight matrix to the network device.

6. The hybrid beamforming transmission method according to claim 4 , wherein the network device is configured to transmit the signal in an analog beamforming manner within the spatial range by: using different analog beamforming weight matrices to transmit the signal in an analog beamforming manner on different time-domain resources; or using different analog beamforming weight matrices to transmit the signal in an analog beamforming manner on different frequency-domain resources; or using different analog beamforming weight matrices to transmit the signal in an analog beamforming manner on different time/frequency resources.

7. The hybrid beamforming transmission method according to claim 1 , wherein the step of determining, by the network device, the set of beamforming weight matrices in accordance with the digital-domain beamforming weight matrix, and selecting the beamforming weight matrix from the set of beamforming weight matrices as the analog-domain beamforming weight matrices for the first UE comprises: determining, by the network device, a spatial range and a set of beamforming weight matrices in accordance with a beam corresponding to the digital-domain beamforming weight matrix, each beam corresponding to the set of beamforming weight matrices being located within the spatial range; receiving, by the network device, an uplink signal within the spatial range in accordance with each beamforming weight matrix in the set of beamforming weight matrices, to acquire an equivalent channel corresponding to each beamforming weight matrix in the set of beamforming weight matrices; and selecting, by the network, the analog-domain beamforming weight matrix from the set of beamforming weight matrices in accordance with the equivalent channel corresponding to each beamforming weight matrix.

8. The hybrid beamforming transmission method according to claim 4 , wherein the spatial range is a range with a beam corresponding to the digital-domain beamforming weight matrix as a center and with a distance between the beam to a boundary of the spatial range as a predetermined range; and the set of beamforming weight matrices are selected in accordance with a set of analog-domain precoding matrices, and each beam corresponding to the set of beamforming weight matrices is located within the spatial range.

9. The hybrid beamforming transmission method according to claim 1 , wherein subsequent to the step of selecting, by the network device, the analog-domain beamforming weight matrix, the hybrid beamforming transmission method further comprises: performing, by the network device, a reception beamforming operation at a digital domain in accordance with the analog-domain beamforming weight matrix selected for the first UE, to acquire an equivalent channel; and re-determining, by the network device, a new digital-domain beamforming weight matrix for the first UE in accordance with the equivalent channel.

10. The hybrid beamforming transmission method according to claim 1 , wherein the number of the beamforming weight matrices selected by the network device from the set of beamforming weight matrices is one or more.

11. A network device, comprising a processor, a memory and a transceiver, wherein the memory is configured to store therein data for the operation of the processor, the transceiver is configured to receive and transmit data, and the processor is configured to read a program stored in the memory, to: determine a digital-domain beamforming weight matrix for a first User Equipment (UE) in accordance with a channel measurement result; determine a set of beamforming weight matrices in accordance with the digital-domain beamforming weight matrix, transmit a signal to the first UE in an analog beamforming manner, and select a beamforming weight matrix from the set of beamforming weight matrices in accordance with a measurement result from the first UE, as an analog-domain beamforming weight matrix for the first UE; and perform hybrid beamforming transmission in accordance with the determined digital-domain beamforming weight matrix and the selected analog-domain beamforming weight matrix.

12. The network device according to claim 11 , wherein the processor is further configured to transmit a downlink reference signal, receive from the first UE a Precoding Matrix Indicator (PMI) acquired by performing downlink channel measurement in accordance with the downlink reference signal, and determine the corresponding digital-domain beamforming weight matrix in accordance with the PMI.

13. The network device according to claim 11 , wherein the processor is further configured to: measure an uplink signal from the first UE to acquire digital-domain Channel State Information (CSI); and determine the digital-domain beamforming weight matrix for the first UE in accordance with the digital-domain CSI and a digital-domain beamforming method adopted thereby.

14. The network device according to claim 11 , wherein the set of beamforming weight matrices correspond to a spatial range, and each beam corresponding to each beamforming weight matrix in the set of beamforming weight matrices is located within the spatial range.

15. The network device according to claim 14 , wherein the processor is further configured to: receive information about an index of the beamforming weight matrix fed back by the first UE with respect to the signal; and determine the corresponding analog-domain beamforming weight matrix in accordance with the information about the index of the beamforming weight matrix fed back by the first UE, wherein the first UE is configured to measure the signal, select the corresponding beamforming weight matrix from the set of beamforming weight matrices in accordance with a measurement result, and feed back the information about the index of the selected beamforming weight matrix to the network device.

16. The network device according to claim 14 , wherein the processor is further configured to transmit the signal in an analog beamforming manner within the spatial range by: using different analog beamforming weight matrices to transmit the signal in an analog beamforming manner on different time-domain resources; or using different analog beamforming weight matrices to transmit the signal in an analog beamforming manner on different frequency-domain resources; or using different analog beamforming weight matrices to transmit the signal in an analog beamforming manner on different time/frequency resources.

17. The network device according to 11 , wherein the processor is further configured to: determine a spatial range and a set of beamforming weight matrices in accordance with a beam corresponding to the digital-domain beamforming weight matrix, each beam corresponding to the set of beamforming weight matrices being located within the spatial range; receive an uplink signal within the spatial range in accordance with each beamforming weight matrix in the set of beamforming weight matrices, to acquire an equivalent channel corresponding to each beamforming weight matrix in the set of beamforming weight matrices; and select the analog-domain beamforming weight matrix from the set of beamforming weight matrices in accordance with the equivalent channel corresponding to each beamforming weight matrix.

18. The network device according to claim 14 , wherein the spatial range is a range with a beam corresponding to the digital-domain beamforming weight matrix as a center and with a distance between the beam to a boundary of the spatial range as a predetermined range; and the set of beamforming weight matrices are selected in accordance with a set of analog-domain precoding matrices, and each beam corresponding to the set of beamforming weight matrices is located within the spatial range.

19. The network device according to claim 11 , wherein the processor is further configured to: after the processor has selected the analog-domain beamforming weight matrix, perform a reception beamforming operation at a digital domain in accordance with the analog-domain beamforming weight matrix selected for the first UE, to acquire an equivalent channel; and re-determine a new digital-domain beamforming weight matrix for the first UE in accordance with the equivalent channel.

20. The network device according to claim 11 , wherein the number of the beamforming weight matrices selected by the processor from the set of beamforming weight matrices is one or more.